The term “central venous catheter” or “CVC,” refers generally, in addition to its ordinary meaning, to a catheter that has been inserted into a vein of the vascular system. Although CVCs have many varied applications, CVCs are frequently used when a patent requires frequent or continuous injections of medications or fluids for nutritional support. Common CVC applications include, but are not limited to, chemotherapy, long-term intravenous antibiotics, long-term pain medications, long-term intravenous nutrition, frequent blood draws, dialysis, and plasmapheresis. Therefore, a CVC can be used to deliver fluids to, or extract fluids from, the cardiovascular system.
In a wide variety of medical applications, the tip of a CVC is advanced into the superior vena cava (“SVC”) from an upper extremity jugular vein or subclavian vein. Other approaches and deployment locations can be used in other applications. CVCs are used in a wide variety of applications; one common application is in the provision of a therapeutic compound into a patient's vascular system.
When a CVC is used for an extended period, blockages can form within the CVC, or can form outside the CVC in the vein between the CVC and the blood vessel wall. For example, a blockage inside the CVC can be caused by drug precipitate or thrombus. Additionally, platelet aggregation or fibrin deposition can completely encase the surface of the CVC, or can form a sac around the distal end of the CVC. Conventionally, such blockages were removed, if at all, either by removing and replacing/cleaning the CVC or while the CVC is in place passing a clot-dissolving compound through the CVC to dissolve the blockage. However, removing the CVC catheter is generally not desirable and introducing a large quantity of clot-dissolving compounds into the vascular system can have negative side effects.